Infusion pump apparatus, method and system

ABSTRACT

An infusion pump system is disclosed. The system includes a syringe having a plunger within the syringe barrel, the syringe having an exit end, at least one temperature determination device adjacent to the syringe, at least one device to determine the distance the plunger has moved with respect to the syringe barrel, and a pump processor in communication with the at least one temperature determination device and the at least one optical sensor, wherein when the controller determines a change in temperature and a corresponding plunger movement, the controller increases or decreases a preprogrammed basal rate of the infusion pump by a predetermined amount for a predetermined time.

CROSS REFERENCE TO RELATED APPLICATION(S)

The present application is a Continuation Application of U.S. patentapplication Ser. No. 13/011,299, filed Jan. 21, 2011 and entitledInfusion Pump Apparatus, Method and System, now U.S. Pat. No. 8,715,224,issued May 6, 2014, which claims priority to U.S. Provisional PatentApplication Ser. No. 61/297,387, filed Jan. 22, 2010 and entitledInfusion Pump Apparatus, Method and System, both of which are herebyincorporated herein by reference in their entireties.

TECHNICAL FIELD

The present disclosure relates to medical devices and more particularly,to an infusion pump apparatus, methods and systems.

BACKGROUND INFORMATION

Many potentially valuable medicines or compounds, including biologicals,are not orally active due to poor absorption, hepatic metabolism orother pharmacokinetic factors. Additionally, some therapeutic compounds,although they can be orally absorbed, are sometimes required to beadministered so often it is difficult for a patient to maintain thedesired schedule. In these cases, parenteral delivery is often employedor could be employed.

Effective parenteral routes of drug delivery, as well as other fluidsand compounds, such as subcutaneous injection, intramuscular injection,and intravenous (IV) administration include puncture of the skin with aneedle or stylet. Insulin is an example of a therapeutic fluid that isself-injected by millions of diabetic patients. Users of parenterallydelivered drugs may benefit from a wearable device that wouldautomatically deliver needed drugs/compounds over a period of time.

To this end, there have been efforts to design portable and wearabledevices for the controlled release of therapeutics. Such devices areknown to have a reservoir such as a cartridge, syringe, or bag, and tobe electronically controlled. These devices suffer from a number ofdrawbacks including the malfunction rate. Reducing the size, weight andcost of these devices is also an ongoing challenge. Additionally, thesedevices often apply to the skin and pose the challenge of frequentre-location for application.

SUMMARY

In accordance with one aspect of the present invention, an infusion pumpsystem is disclosed. The system includes a syringe having a plungerwithin the syringe barrel, the syringe having an exit end, at least onetemperature determination device adjacent to the syringe, at least onedevice to determine the distance the plunger has moved with respect tothe syringe barrel, and a pump processor in communication with the atleast one temperature determination device and the at least one opticalsensor, wherein when the controller determines a change in temperatureand a corresponding plunger movement, the controller increases ordecreases a preprogrammed basal rate of the infusion pump by apredetermined amount for a predetermined time.

Some embodiments may include one or more of the following. Wherein whenthe pump processor determines an upward change in temperature and acorresponding plunger movement away from the syringe exit, the pumpprocessor increases the preprogrammed basal rate of the infusion pump bya predetermined amount for a predetermined time. Wherein when the pumpprocessor determines an downward change in temperature and acorresponding plunger movement towards the syringe exit, the pumpprocessor decreases the preprogrammed basal rate of the infusion pump bya predetermined amount for a predetermined time. Wherein the at leastone temperature determination device is a thermistor. Wherein the atleast one device to determine the distance the plunger has moved withrespect to the syringe barrel is an optical sensor.

In accordance with one aspect of the present invention, an infusion pumpsystem is disclosed. The infusion pump system includes a syringe havingan exit end and a plunger movable within the syringe, at least onetemperature determination device, at least one device to determine theeffect of a temperature change on the movement of the plunger, and apump processor to compensate for the movement of the plunger based on atemperature change.

Some embodiments may include one or more of the following. Wherein thepump processor commands the plunger to move away from the syringe exitby a predetermined distance to compensate for the movement of theplunger based on a temperature change. Wherein the pump processordecreases a preprogrammed basal rate for a predetermined amount of timeby a predetermined amount based on the movement of the plunger based ona temperature change. Wherein the at least one temperature determinationdevice is located adjacent to the syringe. Wherein the at least onetemperature determination device is a thermistor. Wherein the at leastone device to determine the effect of the temperature change on themovement of the plunger is an optical sensor.

In accordance with one aspect of the present invention, an infusion pumpsystem is disclosed. The infusion pump system includes a syringe havingan exit end and a plunger movable within the syringe, at least onetemperature determination device, at least one device to detect theeffect of a temperature change on the movement of the plunger, and apump processor in communication with the at least one temperaturedetermination device and the at least one device to detect the effect ofa temperature change on the movement of the plunger.

Some embodiments may include one or more of the following. Wherein theat least one device to detect the effect of a temperature change on themovement of the plunger is a flow sensor located downstream from thesyringe exit. Wherein the at least one device to detect the effect of atemperature change on the movement of the plunger is an occlusion devicelocated downstream from the syringe exit wherein the occlusion deviceoccludes a flow path, the occlusion device controlled by the pumpprocessor. Wherein the at least one device to detect the effect of atemperature change on the movement of the plunger is at least one binaryvalve located downstream from the syringe exit wherein the at least onebinary valve occludes a flow path, the at least one binary valvecontrolled by the pump processor. Wherein the at least one device todetect the effect of a temperature change on the movement of the plungeris a strain beam located in force relationship with the plunger. Whereinthe at least one device to detect the effect of a temperature change onthe movement of the plunger is at least one potentiometer. Wherein theplunger further comprising a predetermined volume of a material whichundergoes a phase change during a temperature change event. Wherein thematerial is wax and the wax and wherein the wax undergoes a phasechange, moves the plunger forward a predetermined distance whereby theresulting change compensates for the change in volume of the syringe dueto a temperature change.

In accordance with one aspect of the present invention, an infusion pumpsystem is disclosed. The infusion pump system includes a syringe havingan exit end and a plunger movable within the syringe, an occluderlocated downstream from the syringe exit, at least one temperaturedetermination device, and a pump processor in communication with theoccluder and the at least one temperature determination device, whereinthe pump processor activates the occluder based on the temperaturesignals from the at least one temperature determination device.

Some embodiments may include one or more of the following. Wherein whenthe at least one temperature determination device signal indicates atemperature change that exceeds a predetermined threshold, the pumpcontroller activates the occluder. Wherein the pump controller activatesthe occluder between pump deliveries.

In accordance with one aspect of the present invention, a method for thedelivery of fluid by an infusion pump is disclosed. The method includesdetermining the distance a plunger should move to deliver a targetvolume, determining the volume of fluid delivered as the temperaturechanges, determining the target plunger position, and adjusting thetarget plunger position based on the actual movement of a temperaturechange.

In accordance with one aspect of the present invention, a method for thedelivery of fluid by an infusion pump is disclosed. The method includesdetermining a temperature change, determining a rate of change exceeds athreshold, and adjusting a basal rate.

In accordance with one aspect of the present invention, a system, methodand apparatus for temperature compensation in an infusion pump and aninfusion pump with temperature compensation is disclosed. The systemincludes at least one temperature sensor, the temperature sensorcommunicating with at least one processor. The processor determines thetarget plunger position and, based at least at least upon thecommunication from the temperature sensor, may modify the target plungerposition based on the temperature sensed.

Some embodiments may include one or more of the following: an occluderand/or a binary exit valve; at least one optical sensor; at least oneflow sensor.

In accordance with one aspect of the present invention, a system fortemperature compensation in an infusion pump is disclosed. The systemincludes a characterization of the infusion pump at various temperaturesincluding characterization of the volume of fluid pumped, either requestor based on a temperature change. Also, at least one temperature sensor,the temperature sensor to collect data which indicates the temperatureeither inside or outside the infusion pump, the temperature sensorcommunicating the data to a processor. The processor compares the datato the characterization and may determine to adjust the target plungeposition based on the temperature. Some embodiments may include anoccluder and/or a binary exit valve.

In accordance with one aspect of the present invention, an apparatus forinsulating an infusion pump is disclosed. The apparatus includes ahousing of a predetermined size to accommodate an infusion pump, thehousing having at least one insulating layer. The housing including anopening of a predetermined size to accommodate tubing.

Some embodiments may include one or more of the following: a strap;wherein the strap is adjustable; wherein the strap includes a buckle;wherein the apparatus includes an insulating layer that is made from amaterial which, when wetted and refrigerated or frozen, provides acooling effect onto the housing.

In accordance with one aspect of the present invention, an infusion pumpwith a heater including a heating device and at least one temperaturesensor such that the temperature is communicated to a processor whichcontrols the heating device and activates the heating device for asufficient time to maintain the temperature of the infusion pump at apredetermined temperature.

In accordance with one aspect of the present invention, a temperaturelabel for a vial of fluid is disclosed. The temperature label visuallyindicates the temperature of the vial. Some embodiments of this aspectof the invention may include wherein the temperature label isnon-reversible.

These aspects of the invention are not meant to be exclusive and otherfeatures, aspects, and advantages of the present invention will bereadily apparent to those of ordinary skill in the art when read inconjunction with the appended claims and accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features and advantages of the present invention will bebetter understood by reading the following detailed description, takentogether with the drawings wherein:

FIGS. 1A-1B are front and back isometric view of an embodiment of aninfusion pump;

FIGS. 1C-1E are side and front views of the infusion pump assembly ofFIG. 1;

FIG. 1F is a front isometric view of the infusion pump assembly of FIG.1;

FIG. 2 is an illustrative view of one embodiment of a remote controlassembly;

FIG. 3 is a diagrammatic view of the infusion pump assembly of FIG. 1;

FIGS. 4A-4E depict a plurality of hook-and-loop fastener configurationsaccording to some embodiments;

FIG. 5 is an illustration of one embodiment of a holder;

FIG. 6 is an illustration of one embodiment of a user wearing a holder;

FIG. 7 is an illustration of one embodiment of the back of a holder; and

FIG. 8 is an illustration of one embodiment of a vial with a temperaturegauge/label.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS Definitions

As used in this description and the accompanying claims, the followingterms shall have the meanings indicated, unless the context otherwiserequires:

A “device” shall mean a medical device, which includes, but is notlimited to, an infusion pump and/or a controller, i.e., a device forwireless control of another medical device. In some embodiments, theword “device” is used interchangeably with “pump”, “infusion pump”and/or “controller” and/or “Companion” and/or “remote controller device”and/or “remote controller assembly”.

A “Companion” shall mean a device for wireless control of anothermedical device. In the exemplary embodiments, the Companion may alsoinclude a glucose meter/strip reader.

An “input” of a device includes any mechanism by which a user of thedevice or other operator/caregiver may control a function of the device.User inputs may include mechanical arrangements (e.g., switches,pushbuttons, jogwheel(s)), electrical arrangements (e.g., a slider,touch screen), wireless interfaces for communication with a remotecontroller (e.g., RF, infrared), acoustic interfaces (e.g., with speechrecognition), computer network interfaces (e.g., USB port), and othertypes of interfaces.

A “button” in the context of an input such as the so-called “bolusbutton” discussed below may be any type of user input capable ofperforming a desired function, and is not limited to a pushbutton, aslider, switch, touch screen or a jog wheel.

An “alarm” includes any mechanism by which an alert may be generated toa user or third party. Alarms may include audible alarms (e.g., aspeaker, a buzzer, a speech generator), visual alarms (e.g., an LED, anLCD screen), tactile alarms (e.g., a vibrating element), wirelesssignals (e.g., a wireless transmission to a remote controller orcaretaker), or other mechanism. Alarms may be generated using multiplemechanisms simultaneously, concurrently, or in a sequence, includingredundant mechanisms (e.g., two different audio alarms) or complementarymechanisms (e.g., an audio alarm, a tactile alarm, and a wirelessalarm).

“Fluid” shall mean a substance, a liquid for example, that is capable offlowing through a flow line.

A “user” includes a person or animal who receives fluid from a fluiddelivery device, whether as part of a medical treatment or otherwise, ora caregiver or third party involved in programming the device orotherwise interacting with the device to infuse fluid to another.

“Cannula” shall mean a disposable device capable of infusing fluid to auser. A cannula as used herein may refer to a traditional cannula or toa needle.

“Disposable” refers to a part, device, portion or other that is intendedto be used for a fixed duration of time, then discarded and replaced.

“Reusable” refers to a portion that is intended to have an open-endedduration of use.

“Acoustic volume measurement” shall mean quantitative measurement of arelevant volume using acoustical techniques such as those described inU.S. Pat. Nos. 5,349,852 and 5,641,892, which are hereby incorporated byreference herein in their entireties, as well as other techniques.

A “temperature sensor” includes any temperature determinationdevice/mechanism for measuring temperature and communicating temperatureinformation to a controller and/or to a pump processor. The devicesdescribed herein may include one or more temperature sensors formeasuring such things as including, but not limited to, one or more ofthe following: user skin temperature, AVS temperature, ambienttemperature, internal pump temperature, plunger temperature, drive traintemperature and fluid temperatures.

An exemplary use of embodiments of the devices, methods and systemsdescribed here is for the delivery of insulin to people living withdiabetes, but other uses include delivery of any fluid, as describedabove. Fluids include analgesics to those in pain, chemotherapy tocancer patients and enzymes to patients with metabolic disorders.Various therapeutic fluids may include small molecules, naturalproducts, peptide, proteins, nucleic acids, carbohydrates,nanoparticulate suspensions, and associated pharmaceutically acceptablecarrier molecules. Therapeutically active molecules may be modified toimprove stability in the device (e.g., by pegylation of peptides orproteins). Although illustrative embodiments herein describedrug-delivery applications, embodiments may be used for otherapplications including liquid dispensing of reagents for high throughputanalytical measurements such as lab-on-chip applications and capillarychromatography. For purposes of description below, terms “therapeutic”,“insulin” or “fluid” are used interchangeably, however, in otherembodiments, any fluid, as described above, may be used. Thus, thedevice and description included herein are not limited to use withtherapeutics.

Some embodiments of the fluid delivery device are adapted for use bypeople living with diabetes and/or their caregivers. Thus, in theseembodiments, the devices, methods and systems work to delivers insulinwhich supplements or replaces the action of the person living withdiabetes' (referred to as the user) pancreatic islet beta cells.Embodiments adapted for insulin delivery seek to mimic the action of thepancreas by providing both a basal level of fluid delivery as well asbolus levels of delivery. Basal levels, bolus levels and timing may beset by the user or a caregiver by using a wireless handheld userinterface or directly by using a pump. Additionally, basal and/or boluslevels may be triggered or adjusted in response to the output of aglucose meter, which in the exemplary embodiments, is integral to thecontroller. In other embodiments, the controller additionally includes aglucose monitoring device which receives data from a blood glucosesensor. In some embodiments, a bolus may be triggered by a user using adesignated button or other input means located on a device, i.e., on thecontroller and/or on an infusion pump. In still other embodiments, thebolus or basal may be programmed or administered through a userinterface located either on the fluid delivery device/infusion pumpand/or on the controller.

With respect to the names given to screens and types of screens, as wellas proper names given to various features, throughout variousembodiments, these terms may vary.

The systems and methods described herein may be used to control aninfusion pump. For purposes of this description, the various embodimentsof the user interface and the infusion pump may be described withreference to an insulin pump, or a pump which infuses insulin. However,it should be understood that the user interface may be on an infusionpump and/or on a controller. Additionally, where the descriptionpertains to an infusion pump “screen”, this “screen” may also appear ona controller, or may appear on a controller in lieu of a pump.

Infusion pumps contemplated by this description include a pump which maypump any fluid, including, but not limited to, a therapeutic fluid,which includes, but is not limited to, insulin. Thus, where thisdescription describes the exemplary embodiment as pertaining to insulin,this is meant merely for descriptive purpose only as the device is notintended to be limited to insulin. Other fluids are also contemplated.In some embodiments, the methods, systems and devices described hereinmay be used in conjunction with insulin “pens” and/or fluid delivery“pens”, which are known in the art.

The infusion pump may be any infusion pump, for example, but not limitedto, the pump devices shown and described with respect to FIGS. 1A-1F andthose incorporated herein by reference, and include, but are not limitedto, those incorporated herein by reference. In the various exemplaryembodiments, the infusion pump is a syringe-pump, i.e., the fluid ispumped or delivered to the user when a plunger advances in a syringe,pushing the fluid inside the syringe into a cannula. Where the cannulais connected to a user (i.e., the cannula is within the user'ssubcutaneous region) the fluid is delivered subcutaneously to the user.

In the exemplary embodiment, the infusion pump includes hardware forwireless RF communication with a controller. However, in variousembodiments, the infusion pump may be any infusion pump. Referring toFIGS. 1A-1F and 2A-2D, in some exemplary embodiments, the infusion pumpmay include a display assembly 104, however, in other exemplaryembodiments, such as those shown in FIGS. 2A-2D, the infusion pump maynot include a display assembly. In these embodiments, a display assemblywhich may be similar to the one shown in FIGS. 1A, 1D and 1F, or may belarger or smaller, is included on a controller or companion device. Anembodiment of the controller or companion device is shown in FIG. 3.

Referring to FIGS. 1A-1F, an embodiment of an infusion pump assembly 100that may be housed within enclosure assembly 102 is shown. Infusion pumpassembly 100 may include a display system 104 that may be visiblethrough the enclosure assembly 102. One or more switch assemblies/inputdevices 106, 108, 110 may be positioned about various portions of theenclosure assembly 102. The enclosure assembly 102 may include infusionport assembly 112 to which cannula assembly 114 may be releasablycoupled. A removable cover assembly 116 may allow access to a powersupply cavity 118 (shown in phantom on FIG. 1D).

Referring to the infusion pump assemblies shown in FIG. 1A-1F, infusionpump assembly 100 may include processing logic (not shown), which may bereferred to as the pump processor, that executes one or more processesthat may be required for infusion pump assembly 100 to operate properly.Processing logic may include one or more microprocessors (not shown),one or more input/output controllers (not shown), and cache memorydevices (not shown). One or more data buses and/or memory buses may beused to interconnect processing logic with one or more subsystems. Insome embodiments, at least one of the subsystems shown in FIG. 3 is alsoincluded in the embodiment of the infusion pump assembly 200 shown inFIGS. 2A-2D.

Referring now to FIGS. 1A-1F and FIG. 3, examples of the subsystemsinterconnected with processing logic 400 may include but are not limitedto memory system 402, input system 404, display system 406, vibrationsystem 408, audio system 410 motor assembly 416, force sensor 412,temperature sensor (not shown) and displacement detection device 418(which may be referred to as a device to determine and/or detect thedistance the plunger has moved with respect to the syringebarrel/syringe). Infusion pump assembly 100 may include primary powersupply 420 (e.g. a battery) configured to be removable installablewithin power supply cavity 118 and to provide electrical power to atleast a portion of processing logic 400 and one or more of thesubsystems (e.g., memory system 402, input system 404, display system406, vibration system 408, audio system 410, motor assembly 416, forcesensor 412, and displacement detection device 418).

Infusion pump assembly 100 may include reservoir assembly 430 configuredto contain infusible fluid 422. In some embodiments, reservoir assembly430 may be a reservoir assembly similar to that described in U.S. Pat.No. 7,498,563, issued Mar. 3, 2009 and entitled Optical DisplacementSensor for Infusion Devices, which is herein incorporated by referencein its entirety, and/or as described in U.S. Pat. No. 7,306,578, issuedDec. 11, 2007 and entitled Loading Mechanism for Infusion Pump; PCTApplication Serial No. PCT/US2009/060158, filed Oct. 9, 2009 andentitled Infusion Pump Assembly; and U.S. patent application Ser. No.12/249,882, filed Oct. 10, 2008 and entitled Infusion Pump Assembly, nowU.S. Publication No. US-2010-0094222, published Apr. 15, 2010 andentitled Infusion Pump Assembly, all of which are hereby incorporatedherein in their entireties. In other embodiments, the reservoir assemblymay be any assembly in which fluid may be acted upon such that at leasta portion of the fluid may flow out of the reservoir assembly, forexample, the reservoir assembly, in various embodiments, may include butis not limited to: a barrel with a plunger, a cassette or a container atleast partially constructed of a flexible membrane.

Plunger assembly 424 may be configured to displace infusible fluid 422from reservoir assembly 430 through cannula assembly 450 (which may becoupled to infusion pump assembly 100 via infusion port assembly 424) sothat infusible fluid 422 may be delivered to user 454. In thisparticular embodiment, plunger assembly 424 is shown to be displaceableby partial nut assembly 426, which may engage lead screw assembly 428that may be rotatable by motor assembly 416 in response to signalsreceived from processing logic 400. In this particular embodiment, thecombination of motor assembly 416, plunger assembly 424, partial nutassembly 426, and lead screw assembly 428 may form a pump assembly thateffectuates the dispensing of infusible fluid 422 contained withinreservoir assembly 430. An example of partial nut assembly 426 mayinclude but is not limited to a nut assembly that is configured to wraparound lead screw assembly 426 by e.g., 30 degrees. In some embodiments,the pump assembly may be similar to one described in U.S. Pat. No.7,306,578, issued Dec. 11, 2007 and entitled Loading Mechanism forInfusion Pump; U.S. patent application Ser. No. 12/249,882, filed Oct.10, 2008 and entitled Infusion Pump Assembly, now U.S. Publication No.US-2010-0094222, published Apr. 15, 2010 and entitled Infusion PumpAssembly; and U.S. patent application Ser. No. 12/249,891, filed Oct.10, 2008 and entitled Infusion Pump Assembly, now U.S. Publication No.US-2009-0099523 published Apr. 16, 2009 and entitled Infusion PumpAssembly, all of which are herein incorporated by reference in theirentireties.

User Interface

Throughout this description, screens may be referenced with respect tothe “pump” or “Companion” or “Controller”. However, in variousembodiments, a similar screen or a similar method may be accomplished onanother device. For example, where the screen or method is referencedwith respect to the “pump”, a similarly functional screen or method maybe used on the “Companion” or “Controller” in other embodiments. As thisdescription includes embodiments related to both pumps having displaysand pumps having no displays, it should be evident that where theembodiment includes an infusion pump without a display, any screens willbe visible on a Companion or Controller. Similarly, where a methodrequires an interaction between the user and the pump, the interactionmay be accomplished via a switch assembly on the pump where the pump isan infusion pump without a display.

Processing logic which in some embodiments, includes at least oneelement as shown in described with respect to FIG. 3, is used to receiveinputs from a user or caregiver. The user or caregiver uses one or moreinput devices or assemblies, including but not limited to, one or moreof the following: button/switch assembly, slider assemblies, including,but not limited to, capacitive sliders (which may include, for example,including but not limited to any slider described in U.S. patentapplication Ser. No. 11/999,268, filed Dec. 4, 2007 and entitled MedicalDevice Including a Slider Assembly, now U.S. Publication No.US-2008-0177900, published Jul. 24, 2008; and entitled Medical DeviceIncluding a Slider Assembly, all of which are hereby incorporated hereinby reference in their entireties, jog wheel and/or touch screen. Theinfusion device additionally received inputs from internal systems,including but not limited to occlusion detection process 438,confirmation process 440, volume measurement technology (e.g., acousticvolume sensing). Using these inputs, the infusion device producesoutputs, for example including, but not limited to, infusion fluiddelivery to the user or comments, alerts, alarms or warnings to theuser. The inputs are thus either directly from the user to the pump,directly from the pump systems to the processing logic, or from anotherdevice, e.g., a remote controller device (described in more detailbelow), to the pump. The user or caregiver interaction experience thusincludes, but is not limited to, one or more of the following:interaction with a display (either on the infusion pump device itself ora remote controller device or both), which includes but is not limitedto, reading/seeing text and/or graphics on a display, direct interactionwith a display, for example, through a touch screen, interaction withone or more buttons, sliders, jog wheels, one or more glucose stripreaders, and sensing either through touch sensation or audio, one ormore vibration motors, and/or an audio system. Thus, the term “userinterface” is used to encompass all of the systems and methods a user orcaregiver interacts with the infusion pump, to control the infusionpump.

Referring now to FIG. 2, in some embodiments of the infusion pumpsystem, the infusion pump may be remotely controlled using a remotecontroller assembly 300, also referred to as a controller or acompanion. Remote control assembly 300 may include all, or a portion of,the functionality of the infusion pump assembly shown in FIGS. 1A-1F,itself. Thus, in some exemplary embodiments of the above-describedinfusion pump assembly, the infusion pump assembly (not shown, see FIGS.1A-1F, amongst other FIGS.) may be configured via remote controlassembly 300. In these particular embodiments, the infusion pumpassembly may include telemetry circuitry (not shown) that allows forcommunication (e.g., wired or wireless) between the infusion pumpassembly and e.g., remote control assembly 300, thus allowing remotecontrol assembly 300 to remotely control infusion pump assembly 100.Remote control assembly 300 (which may also include telemetry circuitry(not shown) and may be capable of communicating with infusion pumpassembly) may include display assembly 302 and an input assembly, whichmay include one or more of the following: an input control device (suchas jog wheel 306, slider assembly 310, or another conventional mode forinput into a device), and switch assemblies 304, 308. Thus, althoughremote control assembly 300 as shown in FIG. 2 includes jog wheel 306and slider assembly 310, some embodiments may include only one of eitherjog wheel 306 or slider assembly 310, or another conventional mode forinput into a device. In embodiments having jog wheel 306, jog wheel 306may include a wheel, ring, knob, or the like, that may be coupled to arotary encoder, or other rotary transducer, for providing a controlsignal based upon, at least in part, movement of the wheel, ring, knob,or the like.

Remote control assembly 300 may include the ability to pre-program basalrates, bolus alarms, delivery limitations, and allow the user to viewhistory and to establish user preferences. Remote control assembly 300may also include a glucose strip reader 312.

During use, remote control assembly 300 may provide instructions to theinfusion pump assembly via a wireless communication channel establishedbetween remote control assembly 300 and the infusion pump assembly.Accordingly, the user may use remote control assembly 300 toprogram/configure the infusion pump assembly. Some or all of thecommunication between remote control assembly 300 and the infusion pumpassembly may be encrypted to provide an enhanced level of security.

In the exemplary embodiments of the user interface, the user interfacemay require user confirmation and user input. The exemplary embodimentsof the user interface are centered on ensuring the user knows the effectof various interactions on the pump. Many examples will be presentedthroughout this description of the pump communicating the result of theuser's actions to the user. These features ensure the user understandstheir actions and therefore, imparts greater safety onto the user. Onesuch example is throughout the exemplary embodiment of the userinterface, where the user presses the back button on a screen after avalue has been changed, the user interface displays the Cancel Changesconfirmation screen, as shown in FIG. 6. If the user selects “Yes”, theuser interface discards any pending changes, closes the confirmationscreen and goes back to the previous screen (i.e., the screen previousto the screen where the user pressed the Back button). When the actionselection is “No”, on the “Cancel Changes?” confirmation screen, theuser presses the enter button or other depending on the embodiment, andthe user interface closes the confirmation screen and returns to thescreen with pending changes. This feature prevents the outcome where theuser assumes the changes have been implemented, but in fact, they havenot been. Thus, this feature prevents that circumstance and ensures theuser understands that the changes have not been implemented.

Temperature

In various embodiments of the infusion pump, the user may wear theinfusion pump either attached to a belt, attached to another article orclothing or a garment such that the device is worn on the body, or, insome embodiments, attached to an undergarment, in a pocket or, in someembodiments, attached to the skin of the user. The user generally wearsthe infusion pump as close to twenty-four (24) hours a day as possible,and in some cases, removing the device for short periods of time, forexample, but not limited to, during an MRI or other treatment that mayeffect the device and/or while showering/bathing. Thus, during thenormal course of the user's wearing the infusion pump, the infusion pumpmay be exposed to various temperatures, including, temperature swings,which may include positive temperature swings and/or negativetemperature swings. These temperature swings may be the result of theuser stepping out of doors, into a cold room, into a hot room and/orunder a blanket or other warming agent.

The fluid contained in the reservoir while in the pump, which, asdiscussed above, may include, but is not limited to insulin, has athermal expansion coefficient which may be referred to as a generalvolumetric thermal expansion coefficient. Thus, during a temperatureswing/differential/change, whether positive or negative, the fluid, orinsulin, will expand or contract. Various factors may contribute to theexpansion or contraction of the fluid including but not limited to therate of change of the temperature. Thus, in some embodiments, the amountof expansion or contraction may be a function of the temperature.

Additionally, in various embodiments of the various embodiments of thedevices described, the components of the pumps also have thermalexpansion coefficients. These thermal expansion coefficients may varydepending on the material. Thus, where the various components are madefrom different materials, the thermal expansion coefficients may vary.

In some embodiments, a change in temperature may affect a thermalexpansion or thermal contraction of the fluid and/or one or morecomponents of the infusion pump. For example, but not limited to, anincrease in temperature may cause an increase in the diameter of thereservoir/syringe 430 (for illustration only, please refer to FIG. 3).This may be because the relative thermal expansion of the syringecompared with the fluid governs whether fluid is delivered or pulledback. Thus, this in turn may cause any fluid/insulin in the cannula 450to flow backwards, towards the reservoir 430. In this case, a volume offluid/insulin is pulled back into the reservoir. Thus, a subsequentrequest for a delivery by processing logic 400 may only result in thisretracted volume being delivered to the user. Thus, a volume offluid/insulin (the retracted volume) has not been delivered to the userwithout request or knowledge by the user. Another example includestemperature decrease. In some embodiments, a temperature decrease maycause the reservoir 430 to decrease in diameter, causing fluid/insulinto flow to the cannula 450. Thus, an unintended bolus volume isdelivered to this user. In this case, fluid/insulin has been deliveredto the user without request or knowledge by the user.

Thus, in the first example, the user may receive less fluid/insulin thanis required or requested and thus, may experience hyperglycemia. In thesecond example, the user may receive more fluid/insulin than is requiredor requested and thus, may experience hypoglycemia. In either example,the user receives a fluid/insulin volume that is not the same as therequested or programmed therapy and is not notified of the disparity.

In these examples, the reservoir is assumed to be a cylinder. Below is amathematical model of the change in volume of a cylinder (assuming aconstant coefficient of linear expansion, a). This is a model forexplanation purposes. Additional mathematical models may be determinedto accommodate additional assumptions, for example, a shape other than acylinder, or a syringe with a movable plunger.ΔV=V(3αΔT+3α² ΔT ²+α³ ΔT ³)  [EQ#1]

Which may be simplified assuming αΔT<<1 to:

$\begin{matrix}{\frac{\Delta\; V}{V} \approx {3{\alpha\Delta}\; T}} & \left\lbrack {{EQ}{\# 2}} \right\rbrack\end{matrix}$

Thus, the volume change of a cylinder made from polypropylene where thetemperature changes from 30 C to 10 C for polypropylene, which is amaterial with linear coefficient of linear expansion

${\alpha = {86 \times 10^{- 6}\frac{cm}{{cm} \cdot K}}},$would be:

$\begin{matrix}{{\frac{\Delta\; V}{V} \approx {3\left( {86 \times 10^{- 6}\frac{cm}{{cm} \cdot K}} \right)\left( {20\; K} \right)}} = {0.52\%}} & \left\lbrack {{EQ}{\# 3}} \right\rbrack\end{matrix}$

The change in specific volume for water between 30 C and 10 C is about0.40%. The difference between the two (about 0.12%) applied to a 3 ccsyringe or reservoir would be about 3.6 μL. However, in addition, thesyringe plunger may move in response to the thermal expansion dependingon the plunger material and the relationship of the syringe in the pump(e.g., the design of the syringe retention in the pump).

Therefore, there may be a desire to minimize the effect of temperatureon the delivery of fluid. Thus, it may be desired to limit or minimize,and/or characterize, the thermal expansion of the fluid and/or one ormore of the components of the infusion pump. The systems, methods andapparatus described to minimize the effect of temperature on the thermalexpansion of the fluid and/or one of more of the components of theinfusion pump may include one or more of the following exemplaryembodiments.

In some embodiments, selection of materials with predictable andfavorable thermal expansion coefficients may minimize the potentialunder and over delivery of fluids as discussed above. In someembodiments, the syringe material, for example, may be selected to matchthe thermal expansion of the fluid. For example, the linear expansioncoefficient for water at about 20 C is about:

$\begin{matrix}{68.9 \times 10^{- 6}\frac{cm}{{cm} \cdot K}} & \left\lbrack {{EQ}{\# 4}} \right\rbrack\end{matrix}$

Thus, the syringe material may be selected to have an expansioncoefficient close to this value. For example, a blend of polycarbonateand acrylonitrile butadiene styrene (also referred to as “ABS”) could beused to match the thermal expansion coefficient of the fluid. In someembodiments, other plastics, for example, but not limited to,polycarbonate, may be close to the correct expansion coefficient suchthat the volume delivered by the syringe pump due to the expectedtemperature change is minimal and/or acceptable. In some embodiments,the plastic or material selected may be tailored to the slope of thethermal expansion of the fluid.

In some embodiments, the material of the plunger and/or the plunger rodmay be selected to thermally differentially compensate for the change intemperature. In some embodiments, the materials for the syringe, plungerand plunger rod may be selected to thermally differentially compensatefor the change in temperature. Also, or in addition to, in someembodiments, the material of one or more components of the drive train,or any other component of the infusion pump, may be selected tothermally differentially compensate for the change in temperature.

In some embodiments, the materials for any one or more infusion pumpcomponents may be selected to have an opposite thermal coefficient, or athermally compensating material to minimize the thermal expansioneffects of the temperature. For example, in higher temperatures, wherethe infusion pumps syringe expands, the flow of fluid may be negative.In some embodiments, at least one component of the drive train may havea negative thermal constant, thus, having the opposite thermalcoefficient. Thus, upon a temperature increase, the syringe does notexperience a change in volume.

In some embodiments, the use of a material which may undergo a phasechange during a temperature change event may minimize the effect of thetemperature differential/change on the infusion pump. For example, insome embodiments, the plunger may include a predetermined volume of wax,thus, as the temperature increases, the length or position may increasedue to the phase change of the wax. Additional wax features may be addedin some embodiments to prevent flow. In some embodiments, a wax featuremay be added to move the plunger forward a (predetermined) distance suchthat the resulting change in the volume is equal to the square root ofthe diameter of the plunger. Thus, in some embodiments, the use of amaterial which undergoes a phase change in response totemperature/temperature change/differential may be used to compensatefor the change of volume of the syringe due to a temperature change. Insome embodiments, the material which undergoes a phase change inresponse to a temperature change may absorb the energy of the thermaldifferential, thus, for example, where the temperature is increasing,rather than rising the temperature of the infusion pump, the wax, orother phase change material, may melt the wax/phase change material,thus, acting as an energy sink and absorbing the heat.

In some embodiments, the syringe may be constrained in such a way that achange in temperature may cause the plunger to be advanced or withdrawnto compensate for the volume change of the syringe. For example, in someembodiments, the syringe may be held in a metal case, the metals thatmay be used include but are not limited to, steel, aluminum, and/or anymetal with a low coefficient of thermal expansion, which may include,but is not limited to, FeNi36, also known as INVAR®. The plunger may bemade from a material that has a high coefficient of thermal expansion.Thus, in this example, a decrease in temperature may cause the syringeplunger to be withdrawn as the diameter of the syringe barrel isdecreasing. Thus, balancing these effects, the change in the totalvolume may be minimized.

Characterization and Controls Compensation

In some embodiments, characterizing the effect of a change intemperature on the volume of fluid pumped by the infusion device may becompleted. In this embodiment, the pump may be subjected to temperaturevariation (i.e., both positive and negative) and the correspondingresponse by the infusion pump may be recorded. The characterization mayinclude, but is not limited to, varying rates of change (i.e., 1 degreeCelsius per minute, and whether positive and negative, etc), totaltemperature variation (e.g., 10 degrees Celsius, 5 degrees Celsius,etc), and/or position of syringe plunger.

The infusion pump may include one or more devices and/or componentsand/or systems to determine the temperature. In some embodiments, theinfusion pump may include one or more thermistors or other temperaturesensors to determine the temperature. However, in other embodiments,various methods and/or devices and/or systems to determine thetemperature, either directly or indirectly, may be used, including, butnot limited to, one or more of the following: at least one resistancetemperature device (RTD) and/or at least one non-contact infrared device(non-contact IR). The location of the one or more thermistors and/ortemperature determination devices may vary. The locations of one of moreof the thermistors and/or temperature determination devices may include,but is not limited to, the drive screw, any location on the drive train,on the syringe barrel, including but not limited to, printed on thesyringe barrel, the plunger and/or, the printed circuit board. Invarious embodiments, the one or more thermistor(s) and/or temperaturedetermination devices location may be any where away from the heatsources that would render a potentially false reading. In someembodiments, the one or more thermistors may determine the temperatureof one or more locations, including, but not limited to, inside of thesyringe, the outside of the syringe, the inside of the pump, and/or theoutside of the pump. Various controls may be determined based on atemperature model in any one or more of these locations. Thus, in someembodiments, the characterization may be made by taking temperaturereadings both within the syringe and outside of the syringe. In otherembodiments, the characterization may be performed by taking temperaturereadings from outside the pump and inside the pump. In the variousembodiments, the one or more thermistors and/or temperaturedetermination devices are preferably placed in the same location on thepump for use by the user as they were during the characterization.

In some embodiments, the characterization may be completed by measuringthe volume of fluid delivered as a function of temperature. In someembodiments, this may be accomplished by using a thermal chamber and aninfusion set/cannula connected to the reservoir/syringe delivering fluidto a precision scale. However, in other embodiments, this may completedby using a thermal chamber and an infusion set/cannula connected to thereservoir/syringe delivering fluid, and following, determining theposition of the plunger inside the reservoir to determine the totalvolume of fluid delivered.

In some embodiments, in practice, the temperature of the pump (in one ormore locations and/or taken by one or more thermistors) may be measuredand the target position of the plunger may vary as a function oftemperature to compensate for the thermal expansion of the syringeand/or the plunger. The thermal expansion reading may be determined byreferencing the characterization data, as discussed above. Thus, in someembodiments, the target position may be modified based on a look-uptable or function approximation of the volume change of the syringe withtemperature.

In some embodiments, the infusion pump delivers fluid either as a basalor a bolus delivery, and/or a variety thereof. The basal delivery is aprogrammed rate or volume per hour. The infusion pump delivers a volumeof fluid at preset intervals for preset durations of time. The infusionpump may also deliver bolus volumes. A bolus is a requested volume offluid delivered immediately, i.e., at the time the request is made. Oneembodiment of the bolus and basal delivery methods is described in PCTApplication Serial No. PCT/US2009/060158, filed Oct. 9, 2009 andentitled Infusion Pump Assembly, now Publication No. WO 2010/042814,published Apr. 15, 2010 and entitled Infusion Pump Assembly; and U.S.patent application Ser. No. 12/249,882, filed Oct. 10, 2008 and entitledInfusion Pump Assembly; now U.S. Publication No. US-2010-0094222,published Apr. 15, 2010 and entitled Infusion Pump Assembly, all ofwhich are hereby incorporated herein by reference in their entireties.Further, in some embodiments, for example, in the embodiment describedin U.S. Pat. No. 7,498,563, issued Mar. 3, 2009 and entitled OpticalDisplacement Sensor for Infusion Devices, which is herein incorporatedby reference in its entirety, the infusion pump may determine thedistance the plunger must move to deliver a volume of fluid, e.g., abasal volume or a bolus volume. Thus, in some embodiments of theinfusion pump system, the infusion pump may confirm the distance theplunger moved during a delivery using an optical displacement sensor. Insome embodiments, the infusion pump determines the number of motorencoder counts per delivery and confirms movements of the plunger.

However, in various embodiments, the delivery method includes adetermination of the distance the plunger should move (which may bereferred to as the target plunger position) to deliver thedesired/target volume. As discussed above, this may be done bydetermining the number of motor encoder steps, and in other embodiments,may be another method. Regardless, the infusion pump makes adetermination of plunger distance movement.

One example of the characterization and controls compensation method isas follows. The first step may be to characterize the volume deliveredas the temperature changes. This volume may be a function of the amountof fluid contained in the syringe, call this V, and, due to variationsin the thermal expansion properties of plastics and liquids/fluids,also, a function of the temperature, call this T. A function, β(T), maybe found empirically that related the volume change to the temperaturechange.

$\begin{matrix}{{\beta(T)} = {\frac{1}{V}\frac{\Delta\; V}{\Delta\; T}}} & \left\lbrack {{EQ}{\# 5}} \right\rbrack\end{matrix}$

The coefficient β(T) may be approximated as a constant, found as afunction of temperature (as shown above) or possible found as a functionof both temperature and plunger position β(T,x).

Next, the target plunger position may be determined and adjusted. Thetarget position, x, may be adjusted based on the following formula:

$\begin{matrix}{{\Delta\; x} = {\frac{{\beta(T)}V}{\frac{\pi}{4}D^{2}}\Delta\; T}} & \left\lbrack {{EQ}{\# 6}} \right\rbrack\end{matrix}$

Where D is the plunger diameter. If we substitute in

$V = {\frac{\pi}{4}D^{2}x}$(assuming that x=0 where the plunger has reached the end of travel anddisplaced all of the fluid in the syringe) then the relationship may besimplified to:Δx=β(T)xΔT  [EQ#7]

In various embodiments, this correction may be performed in differentways, including, but not limited to, the following. In some embodiments,the correction may be done by delivering on an interval which may bemore frequent than the basal delivery interval, which may be, but is notlimited to, one delivery every e.g., 3 minutes, but in otherembodiments, may be more frequent or less frequent. Further, theposition of the syringe may be adjusted based on the temperature change,maintaining a zero net volume delivered between regular deliveries,e.g., basal and/or bolus deliveries. In some embodiments, this may beused for low basal rates, where the thermally driven volume may exceedthe regularly scheduled basal delivery. This may, however, in someembodiments, require reversing the syringe direction to preventdelivery.

Another embodiment may include applying the correction when thefluid/insulin is scheduled for delivery. Thus, the target plungerposition may be corrected based on the measured temperature change andestimated thermally-driven volume delivery. In some of theseembodiments, the correction may be limited such that the plunger mayonly be driven in one direction.

In some embodiments, modeling may vary, and an assumption may be madewith respect to both length and diameter of the syringe. In addition,assumption may be made regarding the effect of temperature on thethermal expansion coefficient of one or more components of the infusionpump, including, but not limited to, the drive train, plunger, plungerrod, infusion pump housing, and cannula.

In some embodiments, adjusting the plunger target may include adjustingthe target so that it is closer to the exit of the syringe, or furtheraway from the exit of the syringe. In some embodiments, the plungeradvancement may be modified. In other embodiments, the plunger may bedriven backwards to compensate for temperature. However, in someembodiments, depending on the infusion pump, it may be desired to limitadjustment to closer to the exit of the syringe. This may be due to thepotential for backlash.

In some embodiments, a temperature dependant basal rate may bepreprogrammed to the pump for temperature compensation. In theseexamples, the pump processor receives data from at least one temperaturesensor. If the temperature data indicates that the temperature is such,or that the rate of change of temperature is such, that an adjustmentshould be made, the processor may signal to alter the preprogrammedbasal rate. In some embodiments, this alteration may be either anadditional or a decrease of the basal rate by a preset percentage, forexample, an increase of 30% or a decrease of 15%. Of course, these areonly examples, and in these embodiments, the preset alterations may bedetermined to be different from those stated.

In some embodiments, the infusion pump may include at least onetemperature sensor and at least one optical sensor. In some embodiments,the optical sensor may be used to determine that the plunger advanced.In some embodiments, the distance of advancement may also be determined.In some embodiments, a small reflective optical sensor (hereinafter“optical sensor”) that fits into the form factor of the infusion pumphardware is used. The optical sensor has a sensing range that overlapswith the plunger displacements. In the exemplary embodiment any opticalsensor may be used, including, but not limited to a Sharp GP2S60,manufactured by Sharp Electronics Corporation which is a U.S. subsidiaryof Sharp Corporation of Osaka, Japan. This optical sensor contains aninfra red emitting diode and infra red sensing detector in a singlepackage. Light from the emitter is unfocused and bounces off the sensingsurface, some of which makes it back to the detector resulting in thesensed intensity of light that varies as a function of distance/angle tothe reflector. In some embodiments, the sensor is placed such that thereflective surface is the plunger.

In some embodiments, an optical sensor may be used to determine thelevel of fluid in the syringe/reservoir. This information may be used todetermine whether the plunger rod has advanced. Together with thetemperature sensor information, this may provide added data/informationto determine a temperature dependant change.

In some embodiments of the infusion pump system, including thoseembodiments disclosed and described in U.S. Pat. No. 7,498,563, issuedMar. 3, 2009 and entitled Optical Displacement Sensor for InfusionDevices, PCT Application Serial No. PCT/US2009/060158, filed Oct. 9,2009 and entitled Infusion Pump Assembly, now Publication No. WO2010/042814, published Apr. 15, 2010 and entitled Infusion PumpAssembly; and U.S. patent application Ser. No. 12/249,882, filed Oct.10, 2008 and entitled Infusion Pump Assembly, now U.S. Publication No.US-2010-0094222, published Apr. 15, 2010 and entitled Infusion PumpAssembly, all of which are hereby incorporated herein by reference intheir entireties, the infusion pump may include an optical displacementsensor. This sensor may be used to determine whether the plunger rod hasadvanced, either forward or backwards, and the distance of theadvancement. Using this displacement information, together with theinformation from the one or more temperature sensors, the effect of thetemperature change on the plunger may be determined. In turn, thisdetermination may increase the accuracy of controls used to compensatefor a temperature change. This may include, but is not limited to,decreasing the amount of fluid delivered due to a sensed forwardmovement and/or increasing the amount of fluid delivered due to a sensedbackwards movement. In either case, the increase and/or decease of thebasal rate and/or amount and/or the amount of bolus (for example, by apercentage of the amount intended) is by a predetermined amount and fora predetermined time.

In some embodiments, the infusion pump system may include a systemand/or method for adjusting the basal rate and/or bolus amount based ona temperature change. Thus, in various embodiments, where the systemdetermines that a threshold temperature change, either up or down, hasoccurred, the system may automatically, and/or by request and/orconfirmation by the user, enter a mode having a limited period, e.g., aflat pre-set limited time period, e.g., 20 minutes, and/or in someembodiments, the mode may continue until the temperature changethreshold is not longer applicable. In some embodiments, where, forexample, a decreasing temperature gradient is a primary concern, theinfusion pump processor may be pre-programmed with a “decreasinggradient” mode, and the infusion pump may purposefully under deliver inthis mode, i.e., an automatic percentage decrease in the basal rate,and, in some embodiments, also, the bolus, may be instituted tocompensate for a predicated additional delivery of fluid. As discussedabove, determining the percentage change of insulin delivery may dependon the characterization of the infusion pump.

Following, in some embodiments, where, for example, increasingtemperature gradient is the primary concern, the infusion pump processormay be pre-programmed with a “increasing temperature gradient” mode, andthe infusion pump may purposefully over deliver, i.e., an automaticpercentage increase in the basal rate, and, in some embodiments, alsothe bolus, may be instituted to compensate for the predicated decreasein delivery of fluid. As discussed above, determining the percentagechange may depend on the characterization of the infusion pump.

Closed Loop Temperature Compensation

For the purposes of this description, the term “advanced” refers to themovement of a plunger within a syringe or reservoir body. Advancement isnot limited to movement in a particular direction. The syringe has anexit end, which is the end of the syringe in which fluid moves outwardfrom the syringe.

In some embodiments, the system may include one or more devices and/orsensors to determine the effect of the temperature on thesyringe/plunger and/or the pumping of fluid, either towards theuser/cannula or away from the user/cannula. These devices and/or sensorsmay include, but are not limited to, one or more flow sensors, one moreocclusion devices and/or one or more binary valves, and/or one or morestrain beams or sensors and/or one or more optical sensors and/or one ormore temperature sensors and/or one or more ultrasonic range sensorsand/or one or more potentiometers and/or one or more rotor encodersand/or one or more linear encoders.

With respect to optical sensors, in some embodiments, the infusion pumpmay include at least one temperature sensor and at least one opticalsensor. In some embodiments, the optical sensor may be used to determinethat the plunger advanced. In some embodiments, the distance ofadvancement may also be determined. In some embodiments, a smallreflective optical sensor (hereinafter “optical sensor”) that fits intothe form factor of the infusion pump hardware is used. In variousembodiments, the optical sensor has a sensing range that overlaps withthe plunger displacements. In various embodiments any optical sensor maybe used, including, but not limited to one or more of the following:Sharp GP2S60, Sharp GP2S700 and Sharp GP2A240LC, all of which aremanufactured by Sharp Electronics Corporation which is a U.S. subsidiaryof Sharp Corporation of Osaka, Japan. This optical sensor contains aninfra red emitting diode and infra red sensing detector in a singlepackage. Light from the emitter is unfocused and bounces off the sensingsurface, some of which makes it back to the detector resulting in thesensed intensity of light that varies as a function of distance/angle tothe reflector. In some embodiments, the sensor is placed such that thereflective surface is the plunger.

In some embodiments, an optical sensor may be used to determine thelevel of fluid in the syringe/reservoir. This information may be used todetermine whether the plunger rod has advanced. Together with thetemperature sensor information, this may provide added data/informationto determine a temperature dependant change.

In some embodiments of the infusion pump system, the infusion pump mayinclude an optical displacement sensor. This sensor may be used todetermine whether the plunger rod has advanced, either forward (towardsthe syringe exit) or backwards (away from the syringe exit), and thedistance of the advancement. Using this displacement information,together with the information from the one or more temperature sensors,the effect of the temperature change on the plunger may be determined.In turn, this determination may increase the accuracy of controls usedto compensate for a temperature change. This may include, but is notlimited to, decreasing the amount of fluid delivered (i.e., decreasingthe volume of fluid that was scheduled to be delivered, i.e., basalrate, or requested to be delivered, i.e., bolus amount) to a sensedforward movement and/or increasing the amount of fluid delivered due toa sensed backwards movement.

In some embodiments, the infusion pump may include an exit valve and/oran occluder. Thus, in these embodiments, the infusion pump includes atleast one device to prevent the delivery of fluid either from thesyringe to the cannula and/or from the cannula to the user. In someembodiments, the device is activated when the at least one temperaturesensor sends a signal to the processor and the processor determines thatthe temperature change meets a threshold, i.e., that the temperaturechange is large enough to effect a change in delivery due totemperature. In some embodiments, this may activate the occluder and/orexit valve, preventing fluid from flowing into or out of the syringeand/or the cannula. In some embodiments, the occluder and/or exit valvedevice is deactivated when the at least one temperature sensor sends asignal to the processor and the processor determines that thetemperature change no longer meets a threshold, i.e., that thetemperature change is no longer large enough to effect a change indelivery due to temperature. In some embodiments, this may deactivatethe occluder and/or exit valve, allowing fluid to flow out of thesyringe and/or to the cannula and/or to the user. Again, as discussedabove, in some embodiments, the plunger target may be adjusted inresponse to the information from one or more temperature sensors.

In some embodiments, the occluder/exit valve may be closed during theinterval when the infusion pump is not actively delivering fluid so asto prevent inadvertent fluid flow in or out of the syringe/reservoir dueto a change in temperature. During the time when the infusion pump isnot actively delivering fluid, the at least one temperature sensor maycontinue to send signals to the processor indicating temperature. Thisinformation may be used by the control system to determine whether andhow to modify the “next delivery” of fluid, i.e., the next plungertarget. Thus, when the “next delivery” is made, the occluder/exit valvemay open and the fluid is delivered.

Thus, in these embodiments, the occluder/exit valve may act primarily toprevent spontaneous unintended fluid flow that may be caused bytemperature change. The control system may adjust the volume delivery,i.e., plunger target, based on the temperature change such that thevolume of delivered fluid compensates for the temperature change.

In some embodiments, the infusion pump may include a compliantcomponent. In some embodiments, the compliant component may allow thedifference in volume change in the syringe/reservoir while maintaining apressure constant. Thus, in these embodiments, controller compensationmay not be necessary to compensate for temperature change when theoccluder/exit valve is open as there would not be a pressure build upfrom a change in temperature.

In some embodiments, once a threshold temperature change has beendetermined, the occluder/exit valve may be closed and the plunger rodmay be allowed to float, i.e., the plunger rod may become disengagedwith the drive train. A change in pressure would thus allow the plungerto float and find equilibrium, thus adjusting without the need forcontroller compensation in response to a temperature change.

In some embodiments, the infusion pump may include at least one flowsensor, including, but not limited to, a flow sensor positioned in theexit fluid path. The flow sensor may detect the flow of fluid. Thisinformation may be correlated with delivery instructions and adetermination may be made whether the fluid delivered was requestedand/or a proper delivery. In some embodiments, where flow is detectedand it is determined that the fluid delivered was not requested and/ornot a proper delivery, the occluder and/or exit valve may be closed.Thus, in some embodiments, a flow sensor may determine fluid flow,either inward or outward, and where this is not an expect event, theinfusion pump may activate at least one mechanism, including, but notlimited to, an occluder and/or a valve to prevent the continued flow offluid. Additionally, the flow information may be used to determine theamount or volume of fluid that has been delivered or has flowed inwardand this information may be used to alter the plunger target during thenext scheduled or requested delivery (e.g., basal or bolus), or, in someembodiments, may be used to alter the delivery schedule. In someembodiments, this may be completed without user interaction. In someembodiments, an alert may be sent to the user and the user must acceptthe proposed course or action to alleviate the under or over delivery offluid.

In some embodiments, the infusion pump may include one or more opticalsensors. These sensors may be placed in the infusion pump to determinethe level of fluid in the syringe/reservoir. The one or more opticalsensors may determine the level of fluid before the processor signalsthe drive train to advance the plunger and after. Thus, the volumedifference may be determined before and after the plunger is advanced.However, the at least one optical sensor may, in some embodiments,collect data a preset intervals, regardless or whether the drive trainhas been activated. Thus, the at least one optical sensor may collectinformation to determine when and whether the plunger has advancesand/or when and whether fluid has been delivered or pulled in. Thus, theat least one optical sensor may collect data for the processor todetermine when a non-requested delivery event may have occurred. Theprocessor may correlate this information with the at least onetemperature sensor and thereby determine whether the infusion pump isexperiencing a temperature related effect. In some embodiments, theprocessor may alert the user. In some embodiments, the information maybe used to instigate a control algorithm to compensate for thetemperature change effect using, for example, but not limited to, thevarious embodiments discussed herein.

In some embodiments, a strain beam may be used to identify a plungermoving away from the exit of the syringe. In these embodiments, thestrain beam may be positioned relative to the plunger rod such thatwhere the plunger rod begins to move away from the syringe exit, thestrain beam will sense the strain. In some embodiments of the infusionpump system, the infusion pump includes a strain beam that may be usedto detect and/or identify occlusions. The strain beam and methods maybe, in some embodiments, similar to those described in U.S. patentapplication Ser. No. 12/249,882, filed Oct. 10, 2008 and entitledInfusion Pump Assembly, now U.S. Publication No. US-2010-0094222,published Apr. 15, 2010 and entitled Infusion Pump Assembly; and PCTApplication Serial No. PCT/US2009/060158, filed Oct. 9, 2009 andentitled Infusion Pump Assembly, now Publication No. WO 2010/042814,published Apr. 15, 2010 and entitled Infusion Pump Assembly, all ofwhich are hereby incorporated herein by reference in their entireties,which are hereby incorporated herein by reference in their entireties.However, together with the at least one temperature sensor, a strainbeam may determine whether a particular temperature change has resultedin plunger movement. Where plunger movement is detected due to atemperature change, the infusion pump may alert the user. In someembodiments, the system may correlate a change in strain with a changein temperature.

Temperature Maintenance

As discussed above, there may be a desire to maintain the temperature ofan infusion pump to avoid any consequences from a temperature change. Insome embodiments, to minimize or prevent the above-described effects oftemperature changes on the infusion pump and delivery of fluid, one ormore various apparatus and/or systems may be employed to maintain thetemperature of the infusion pump.

In some embodiments, the infusion pump includes a heater device. Theheater device may receive instructions from the processor. The heaterdevice may be located anywhere in or on the infusion pump, however, insome embodiments, the heater device is located within the infusion pumphousing. In some embodiments, the heater device is powered by a powersource or battery inside the infusion pump. However, in someembodiments, the power source may be outside the infusion pump.

The heater source may be any heating source desired, however, in theexemplary embodiment, the heating source may be a KAPTON® (PolyimideFilm) Heater kit, part number KH-KIT-EFH-15001 and available fromOmega.com®. In some embodiments, at least one temperature sensor islocated in or on the infusion pump. The at least one temperature sensorcommunicates information to the processor. Based on the temperaturesensor data, the processor may act as a thermostat and power the heatersource to maintain the temperature in the infusion pump at a desiredtemperature. In some embodiments, the desired temperature may be between15 and 30 degrees Celsius, but in other embodiments, the maintenancetemperature may be different. In some embodiments, it may be desirableto maintain the temperature at the higher end.

In some embodiments the syringe/reservoir may be contained in a metalcase in the infusion pump. The metal case may increase the conduction ofheat between the heater element and the syringe/reservoir.

In some embodiments, the at least one heater element may be located inone or more locations inside the infusion pump and one or more of theselocations may be selected to maintain the temperature of one or morecomponents of the infusion pump, including, but not limited to, thesyringe, fluid, plunger, housing, plunger rod and/or the drive train.

In some embodiments, the at least one heater elements may additionallyincrease the power source and/or battery life in the infusion pump.Maintaining the temperature at or about 35 degrees Celsius may bebeneficial to battery life and/or performance.

In some embodiments, it may be desirable to utilize the user's body as aheat sink, wearing the infusion pump close to the user's skin. This maybe accomplished using various devices and apparatus, including but notlimited to one or more of the following.

A hook and loop system fastener system, for example, but not limited toone offered by VELCRO® USA Inc. of Manchester, N.H., may be utilized toallow for easy attachment/removal of an infusion pump from the user.Accordingly, an adhesive patch may be attached to the skin of the userand may include an outward facing hook or loop surface. Additionally, asurface of infusion pump 114 may include a complementary hook or loopsurface. Depending upon the separation resistance of the particular typeof hook and loop fastener system employed, it may be possible for thestrength of the hook and loop connection to be stronger than thestrength of the adhesive to skin connection. Accordingly, various hookand loop surface patterns may be utilized to regulate the strength ofthe hook and loop connection.

Referring also to FIGS. 4A-4E, five examples of such hook and loopsurface patterns are shown. Assume for illustrative purposes that onesurface of infusion pump housing is covered in a “loop” material.Accordingly, the strength of the hook and loop connection may beregulated by varying the pattern (i.e., amount) of the “hook” materialpresent on the surface of adhesive patch. Examples of such patterns mayinclude but are not limited to: a singular outer circle 220 of “hook”material (as shown in FIG. 4A); a plurality of concentric circles 222,224 of “hook” material (as shown in FIG. 4B); a plurality of radialspokes 226 of “hook” material (as shown in FIG. 4C); a plurality ofradial spokes 228 of “hook” material in combination with a single outercircle 230 of “hook” material (as shown in FIG. 4D); and a plurality ofradial spokes 232 of “hook” material in combination with a plurality ofconcentric circles 234, 236 of “hook” material (as shown in FIG. 4E).

In another embodiment, a holder, pouch, sack, container or other type ofhousing (generally referred to as a “holder”) may be sized toaccommodate an infusion pump. In some embodiments, the holder may beconstructed to include multiple layers including but not limited to, oneor more insulating layers. In some embodiments, one or more of thelayers may include a fabric that when wetted and refrigerated or frozen,the layer provides a cooling effect. This layer may be desired in warmerclimates or in situations where the user's infusion pump may be exposedto the sun or a warm environment. In some embodiments, the one or morelayers of material may be highly absorbent material. In someembodiments, the holder may include one or more canisters of isopropylalcohol which may, when deployed, be absorbed into the highly absorbentmaterial of the holder and provide evaporative cooling to the infusionpump. In various embodiments, the holder may include alternative and/oradditional methods, systems and/or devices for cooling the infusionpump.

In some embodiments, the holder may include one or more temperaturemeasurement devices and/or temperature sensors that may transmitinformation to the infusion pump and/or a controller. The one or moretemperature sensors may communicate the temperature of the holder andeither deploy the one or more canisters of alcohol and or alert theinfusion pump/user/controller and/or turn on the heating source, basedon the temperature sensor. In some embodiments, the heating and/orcooling may be triggered by reaching a threshold change in temperature.Thus, in some embodiments, the holder may provide for a closed-loopsystem for maintaining the temperature for the infusion pump.

Referring now to FIG. 5, some embodiments of the holder 500 include anoutside layer 502, an inside layer 504 and an inner pocket 506. Thepocket 506 may include additional cushion or insulation to both protectthe infusion pump from outside forces and/or temperature change. Theholder 500 may include a fastener along the front, top or the side. Insome embodiments, the holder 500 may include the holder may include apull down flap (not shown) on the front to expose the screen and/orinput assemblies (e.g., including but not limited to buttons, sliders,and/or jog wheels). In some embodiments, the flap may be secured closedusing a hook-and-loop system. In other embodiments, the flap may besecured using any other fastener system including, but not limited to,snaps, buttons, magnetic closures and zippers.

In some embodiments, the holder 500 may be attached to a strap 508designed to be attached to the user (see FIG. 6 for example). However,in various embodiments, the strap 508 may be elastic and/or adjustableand may include at least one closure device. Although shown in FIG. 6 asbeing worn about the mid section of a user 510, the holder 500 may beworn anywhere the user desires.

Referring now to FIG. 7, an embodiment of the back of the holder 500 isshown. In some embodiments, the holder may include a clip 512 which maybe referred to as a “belt-clip” or another type of clip configured suchthat it securely and removably fits over a belt, handle, piece ofclothing or other. In some embodiments, the holder 500 may additionallyinclude an opening 514 for tubing 516 to fit through. In someembodiments, the infusion pump (not shown) may be contained inside theholder 500 and the holder worn close to the insertion site (not shown)on the user such that minimal tubing 516 is exposed to the outsidetemperature. Thus, embodiments of the holder 500 including an opening514 for tubing may be beneficial for maintaining the temperature of thetubing 516 and/or the fluid in the tubing.

In some embodiments, a plastic material for example, a Press n'Seal, oranother material of similar behavior, may be used to attach and maintainthe infusion pump against the user's body. In other embodiments, a cuffor band fitted against the leg, midsection or arm, for example, of auser may include a pouch for the infusion pump. In other embodiments,the infusion pump may be maintained in position against the skin throughinner pockets, bra pockets, etc.

Various embodiments are described herein for both utilizing the user'sbody heat and/or a heating element to maintain the temperature of theinfusion pump. However, additional devices and apparatus are within thescope of the invention. Further, various methods, systems and apparatusfor maintaining the temperature of an infusion pump may include at leastone temperature sensor.

Insulin Temperature

Described herein are various methods, systems, devices and/or apparatusfor maintaining the temperature of an infusion pump. Inherent in atleast some of these embodiments is the maintenance of the infusiblefluid/insulin temperature. It is well know that manufacturers of insulinrecommend that the temperature of insulin not exceed a high and a lowtemperature. Additionally, it may be beneficial to maintain fast-acting(e.g., HUMALOG®, NOVOLOG®) at room/ambient temperature (e.g., between 59and 86 degrees Fahrenheit) once the vial has been used, i.e., themanufacturer recommends storing insulin in a refrigerated area, e.g.,between 36 and 46 degrees Fahrenheit, until the vial is used. From thatpoint on, it is recommended that the vial be stored at room temperature.

As insulin may be less effective or not effective once it has reached anon-recommended temperature, it may be beneficial for a user to knowwhether the insulin has been properly stored, whether while in transit,in the refrigerator or while in use.

Referring to FIG. 8, in one embodiment, a stick-on temperature gauge 520may be placed on a vial 522 of fluid, and in some embodiments, on a vialof insulin. The gauge may tell the user the current temperature of thevial. In some embodiments, the temperature may be indicated as variousshades of red and blue, indicating various temperatures towards the highand low range. In some embodiments, once the temperature has reachedeither the maximum or minimum temperature (which is predetermined andmay, in some embodiments, be 35 and 87 Fahrenheit respectively), thegauge becomes non-reversible, thus indicating instantly to the user thatthe insulin has reached either a maximum or minimum temperature.

Any stick-on temperature gauge may be used including a non-reversibletemperature label such as a Non-Reversible Temperature Labels, 3Temperature Ranges, part number TL-3 available from Omega.com®, oranother similar temperature label. As discussed above, in someembodiments, a Reversible Temperature Label may be used or a label withboth reversible and non-reversible components.

While the principles of the invention have been described herein, it isto be understood by those skilled in the art that this description ismade only by way of example and not as a limitation as to the scope ofthe invention. Other embodiments are contemplated within the scope ofthe present invention in addition to the exemplary embodiments shown anddescribed herein. Modifications and substitutions by one of ordinaryskill in the art are considered to be within the scope of the presentinvention.

What is claimed is:
 1. A medical pump system comprising: a syringehaving a plunger movable within the syringe barrel; at least onetemperature determination device; at least one device to determine thedistance the plunger has moved with respect to the syringe barrel; and apump processor in communication with the at least one temperaturedetermination device and the at least one device to determine thedistance the plunger has moved with respect to the syringe barrel,wherein when the pump processor determines a change in temperature and acorresponding plunger movement, the pump processor increases ordecreases a preprogrammed basal rate of the medical pump.
 2. The systemof claim 1, further comprising wherein when the pump processordetermines an upward change in temperature and a corresponding plungermovement, the pump processor increases the preprogrammed basal rate ofthe infusion pump by a predetermined amount for a predetermined time. 3.The system of claim 1, further comprising wherein when the pumpprocessor determines a downward change in temperature and acorresponding plunger movement, the pump processor decreases thepreprogrammed basal rate of the infusion pump by a predetermined amountfor a predetermined time.
 4. The system of claim 1, further comprisingwherein the at least one temperature determination device is athermistor.
 5. The system of claim 1, further comprising wherein the atleast one device to determine the distance the plunger has moved withrespect to the syringe barrel is an optical sensor.
 6. An infusion pumpsystem comprising: a syringe having a plunger movable within thesyringe; at least one temperature determination device; at least onedevice to detect the effect of a temperature change on the movement ofthe plunger; and a pump processor in communication with the at least onetemperature determination device and the at least one device to detectthe effect of a temperature change on the movement of the plunger. 7.The system of claim 6, wherein the at least one device to detect theeffect of a temperature change on the movement of the plunger is a flowsensor located downstream from the syringe exit.
 8. The system of claim6, wherein the at least one device to detect the effect of a temperaturechange on the movement of the plunger is an occlusion device locateddownstream from the syringe exit wherein the occlusion device occludes aflow path, the occlusion device controlled by the pump processor.
 9. Thesystem of claim 6, wherein the at least one device to detect the effectof a temperature change on the movement of the plunger is at least onebinary valve located downstream from the syringe exit wherein the atleast one binary valve occludes a flow path, the at least one binaryvalve controlled by the pump processor.
 10. The system of claim 6,wherein the at least one device to detect the effect of a temperaturechange on the movement of the plunger is a strain beam located in forcerelationship with the plunger.
 11. The system of claim 6, wherein the atleast one device to detect the effect of a temperature change on themovement of the plunger is at least one potentiometer.
 12. The system ofclaim 6, wherein the plunger further comprising a predetermined volumeof a material which undergoes a phase change during a temperature changeevent.
 13. The system of claim 12, wherein the material is wax and thewax and wherein the wax undergoes a phase change, moves the plungerforward a predetermined distance whereby the resulting changecompensates for the change in volume of the syringe due to a temperaturechange.